钴基高温合金的激光成型性能研究  

Laser Forming Properties of Cobalt Base Superalloy

作　　者：何波[1] 楚莎莎[1] 张洪宇[2] 韦华[2] 

机构地区：[1]沈阳航空航天大学机电工程学院,辽宁沈阳110136 [2]中国科学院金属研究所高温合金研究部,辽宁沈阳110016

出　　处：《稀有金属》2017年第4期350-355,共6页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51371173);辽宁省自然科学基金项目(2013024011)资助

摘　　要：采用光纤激光器和同步送粉激光成型工艺技术,实验时通氩气进行真空保护,通过一定的激光工艺参数(激光功率1800 W,扫描速度5 mm·s^(-1),送粉速度18 g·min^(-1),光斑直径3 mm)在45号钢基板上成功获得钴基高温合金块体样品。通过X射线衍射(XRD)、扫描电子显微镜(SEM)和能量分散谱(EDS)分析以及室温拉伸和耐磨实验研究钴基合金的激光成型件性能。结果表明钴基高温合金与基体之间形成良好的冶金结合,激光成型后的微观组织多为均匀细小的枝晶,由于存在重熔区,使得部分枝晶发生粗化现象,但无明显缺陷,主要由M_6C,Cr_(23)C_6,Cr Co金属间化合物和γ-Co基体相组成;成型件样品的拉伸断裂断口平整,无颈缩现象,属于脆性断裂,其断裂过程是韧窝-类解理的复合断裂;成型件样品磨损表面存在犁沟磨痕,磨损前后质量损失很小,耐磨性能优良,耐磨机制主要是磨粒磨损、黏着磨损、氧化磨损。The laser experiment was carried out by vacuum protection,and blocks of cobalt base superalloy were successfully obtained on the 45 Steel matrixes by using fiber laser,synchronous powder feeding system and a certain laser parameters（laser power was1800 W,scanning speed was 5 mm·s^（-1）,powder feeding speed was 18 g·min^（-1）beam diameter was 3 mm）. Laser forming properties of cobalt base superalloy were studied by means of scanning electronic microscopy（SEM）,energy dispersive spectrometer（EDS）,X-ray diffraction（XRD） techniques,room-temperature tensile test and wear resistance experiments. The results showed that good metallurgical bonding could be obtained between cobalt base superalloy and matrix; the most microstructure of laser forming part was uniform and fine dendrite,due to the presence of the heavy re-melting district,coarsening phenomenon occurred in dendrite,but there was no obvious defects; the laser-formed material mainly consisted of phases of M6C,Cr23C6,Cr-Co intermetallic and γ-Co matrix,tensile fracture of forming part sample was smooth,and there was no necking phenomenon,so the tensile fracture was brittle fracture,the fracture mechanism was mixed mode fracture of dimple and cleavage-like fracture; there was furrow wear scar on the worn surface of forming part sample,and mass loss was small before and after wear resistance experiments,so the formed block had a good wear-resistant property,the main wear mechanisms of formed block were abrasive wear,adhesive wear and oxidation wear.

关 键 词：激光成型工艺技术 钴基高温合金 显微组织 拉伸性能 耐磨性能 

分 类 号：TG146[一般工业技术—材料科学与工程]